Emission Factors and Source Profiles of Volatile Organic Compounds in the Petroleum Refining Industry through On-Site Measurement from Multiple Refineries

The petroleum refining industry is the key contributor to industrial volatile organic compounds (VOCs). To establish refined emission factors (EFs) and a source profile, 76 samples from eight refineries were collected using 33 processes. Arithmetic and weighted average methods were used to produce composites of the source profiles. EFs of eight emission sources (0.027–0.96 kg of VOCs/t of crude) were estimated and further classified with different control technology levels. EFs of all refineries ranged from 0.67 to 2.77 kg of VOCs/t of crude. Equipment leak (EL) was the largest emission source (37.65–76.70%), followed by storage tank (ST), loading operation (LO), and wastewater collection and treatment systems (WT). EFs of the EL, ST, WT, LO, cooling tower, processing vent (PV), stationary combustion, and flare were 0.96 ± 0.45, 0.28 ± 0.18, 0.17 ± 0.12, 0.093 ± 0.091, 0.070 ± 0.070, 0.028 ± 0.017, 0.010 ± 010, and 0.027 ± 0.023 kg of VOCs/t of crude, respectively. Alkanes made the largest contribution to the petroleum refining industry, followed by OVOCs and aromatics. Ethane, propane, isobutane, n-butane, isopentane, and n-pentane were the major species. Toluene, benzene, ethylene, and propene in EL, n-butyl acetate and acetone in ST, toluene and benzene in WT, MTBE in LO, and n-hexane in PV were dominant in the corresponding sources.